Question

Although glucose enters the renal tubule during the first step of urine formation, it is actively transported back into blood during this second step in urine formation

Answer 1

The correct answer will be- true

Step-by-step explanation:

Glucose is absorbed by the tubules of the kidney while urine formation which if not absorbed will be lost along with the urine.

During the first step of the urine formation, the Glucose is absorbed by the SGLT2 cotransporter which also symports the sodium along with glucose in the tubule.

This absorbed glucose is transported to the blood capillaries through passive diffusion to maintain them once in the tubule.

The glucose is absorbed so that no glucose is lost along with urine but again backflow to the blood capillaries to maintain the glucose level.

Thus, true is the correct answer.

Answer 2

Right, the SGLT (sodium-glucose transporters are active on the proximal tubule nephrons.

Step-by-step explanation:

Sodium-glucose transport proteins, also called sodium-glucose transporters or SGLTs, are a family of glucose transporters found in the mucosa of the small intestine (SGLT1) and in the cells of the proximal tubule of nephrons in the kidney (SGLT1 and SGLT2).Its function is to reabsorb glucose from the lumen of the renal tubules towards the interior of the peritubular cells, or from the lumen of the small intestine to the cells of the intestinal mucosa. The transport process requires an energy source for its realization coming from the eletrochemical gradient created by the primary transport.

There are several types, the most important of which are SGLT1 and SGLT2:

SGLT1 is the key transporter for the absorption of glucose in the gastrointestinal tract, however in the kidney its importance is less, it represents around 10% of the reabsorption of glucose that takes place in this organ.SGLT2 is a transporter that is mainly found in the kidney and makes possible the reabsorption of glucose that is found in the glomerular filtrate that originates the urine. In diabetes, its inhibition through drugs such as canagliflozine or dapagliflozine, contributes to glucose control by lowering its threshold of renal reabsorption (see glycosuria)

Sources:

Guyton y Hall Tratado de fisiologia medica 12ª Edicion + StudentConsult